US Patent 9341119 Cooling air system for aircraft turbine engine

In one aspect, a turbine engine is provided. The engine includes a fan, a core engine case configured to receive a core airflow, and an inner fan case. An inner air bypass is defined between the core engine case and the inner fan case, and the engine further includes an outer fan case, an outer air bypass defined between the inner fan case and the outer fan case, a first heat exchanger arranged in the core engine case, the first heat exchanger providing heat exchange between the liquid and the core airflow to cool the core airflow, and a second heat exchanger arranged in the outer air bypass. The second heat exchanger is fluidly coupled to the first heat exchanger to receive the cooled core airflow. The second heat exchanger provides heat exchange between cooled core airflow and the second portion of airflow to further cool the cooled core airflow.